diff --git a/src/command.lua b/src/command.lua
index c859bfd..c4e78ea 100644
--- a/src/command.lua
+++ b/src/command.lua
@@ -1,4 +1,4 @@
-if type(data) == "string" then
+if type(data) == "string" and data ~= nil then
     local cmd, value = data:match("([^=]+)=([^=]+)")
     if cmd == nil then
         data = data:lower()